It's amazing that that many processors work on single silicon wafer. Usually some processors have flaws and are tossed away after being separated from others on the same silicon wafer. My guess is that it's still true but to a much lesser degree and they a have a technique to isolate flawed processors so that have no effect on the rest of the system.

Manufacturing must have advanced a great deal in recent years.

And the processing speed when all the processors are so close is incredible.